This pie is one of the favorite dessert in the Pennsylvania Amish community.

Set the oven rack in the lower third of the oven. Preheatthe oven at 400 °F (200°C).
Mix baking soda and boiling water and let cool at room temperature.
Beat the egg yolk in a small bowl. Add molasses and cooled mixture and mix until well blended.
In a medium bowl, mix flour, cinnamon, nutmeg, clove, ginger, brown sugar and salt. Cut in butter with a pastry blender OR blend dry ingredients in the food processor, add butter and pulse a few times.
Put a third of the dry ingredients in the pie shell, cover with half of liquid preparation. Sprinkle another third of dry ingredients and cover with remaining liquid preparation. Sprinkle remaining dry ingedients.
Bake in the oven 10 Minutes; reduce temperature at 325 °F (165 °C) and bake 30 Minutes until the center of the pie is set.